Alloy.



UNITED STATES PATENT OFFICE.

PAUL RICHARD KUEHNRIGH, 0F SHEFFIELD, ENGLAND.

ALLOY.

No Drawing.

To all whom it may concern:

Be it known that I, PAUL RICHARD KUEHNRICH, steel manufacturer, subject of the King of England, residing at Sheflield, in England, have invented a certain new and useful Improved Alloy; and I declare the following to'be a full, clear, and exact description of the same.

The object of this invention is to provide an improved alloy possessing the qualities and endurance almost exclusivel associated heretofore .with high speed too steel. An alloy according to the present invention comprises a base of nickel, chromium and silicon, to which a substantial quantity of aluminium has been added. It is to the presence of this aluminium in the alloy that its peculiar properties are due, enabling it to be used as a substitute for high speed steel. The hardness of the alloy is determined by the amount of alumlnium, but when excessive quantities ofthe latter are added'the allo becomes too brittle for use for hi h spee tools.- The nickel may be partial y replaced by cobalt.

In carrying out the present invention a base alloy of nickel, chromium and silicon is first melted. The proportion of chromium ma vary from about 10% to 35% or possib y more, while the silicon content may also vary, 3% or even less givin satisfactory results but the amount of $1 iconmay be considerably increased. When the base, which should preferably contain not less than i% of carbon, is sufficiently molten there is addeda substantial quantity of aluminium, about 6% of the whole, but the percentage of aluminium may va from 3% to 20% according to the har ness required.

When the aluminium has been melted and proper admixture has occurred the alloy teemed.

The alloy thus made is cast into tools in metal or sand molds, the former being preferred. The castin are ready for use without any additional h eat treatment, their cutting edges merely requirinfi to be ground. Thpy are found to be exce ent high speed toos.

Although the alloy according to this invention is mainly intended for the manufacture of high speed cutting tools it may be used for other purposes, such as the valves of internal combustion motors, where Specification of Letters Patent.

and from 3% to 20% of aluminium. 4. A metal alloy having the following approximate analys1s:-

Patented uly 30, 1918.

Application filed June 17, 1916. Serial No. 104,212.

Ferro -chrome (containing about 70% chromium and 1% to 6% carbon) 8 lbs. Nickel 21 lbs. Silicon 1 lb. 11 ozs. Aluminium -Q. 2 lbs. 8 ozs.

- In the base alloy of nickel, chromium and silicon in about. the relative proportions described the nickel may be partially replaced by cobalt.

. What I claim and desire to secure-by Let ters Patent is 1. A metal alloy composed of nickel, ap-

proximately 10% to 35% of chromium, ap-v proximately 3% to 7% of silicon, and from 3% to 20% of aluminium.

2. A metal alloy composed of nickel, ap} proximately 10% to 35% of chromium, ap-

proximately 5% of silicon, and approximately 6% of aluminium.

3; A metal alloy composed of nickel, approximately 10% to 35% of iron and chromium, approximately 3%v to 7% of silicon,

Nickel -i. 63. 26%.

' Iron 5. 77% Chromium 16. 83 Carbon 1. 41% Silicon 5. 10% Aluminium 7. 60%

In testimony whereof I afiix my signature in presence of two witnesses.

PAUL RICHARD KUEHNRICH. 

